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Fisheries notes

2.
Fish Stocks
• The actual number of fish
• Sometimes the area and the species are defined
Ex: “The Atlantic Coast Striped Bass Stocks are stronger than they were in the 1980’s”
• Other times people use the word in a general sense

3.
EEZ
• The US Exclusive Economic Zone is claimed
out from our shores to 200 miles out to sea
• The US maintains that this region is ours,
exclusively to use and no other country is
allowed here without our permission
• We use our EEZ for things like fisheries,
military uses, oil drilling, mining, etc.

7.
Bycatch (AKA Trash Fish)
• Animals captured while fishing that are not the targeted species
and are frequently thrown back dead or dying
• Examples:
-Sea Turtles in the
Shrimp Fishery
-Dolphin in the
Tuna Industry
-You may be
familiar with
Sea Robins as
bycatch in
recreational
fluke fishing

8.
More on Bycatch
• The Bad News…For every pound of shrimp you
consume, up to 20 pounds of bycatch is thrown
back, much of it dead
• The Good News…Consumers can speak with their
wallets to encourage change within the industry:
• TED’s (Turtle Excluder Devices) & BRD’s (Bycatch
Reduction Devices)
http://www.youtube.com/watch?v=y71cgxmyMO4

9.
How TEDs and BRDs work
In the top diagram the trawl net has no BRD fitted. All animals that
enter the net are caught in the cod end, including prawns, turtles and
unwanted fish species.
In the bottom diagram, the trawl net has two types of BRD fitted. The
turtle excluder device stops turtles from entering the cod end and
forces them out through a flap on the trawl net. Because fish have a
tendency to swim against a current, the fish eye allows them to swim
out through the top of the net and avoid capture in the cod end. Even
with BRDs fitted, prawns are still caught in the cod end.

10.
Overfishing
• So if we don’t let other countries into our EEZ,
why do we still have trouble with overfishing?
– We, ourselves, are taking too many fish
– Fish don’t know boundaries
• Why do we fish further and further from our
coasts?
– We are taking our coastal fish at a more rapid rate
than they can replenish

13.
Other Frequently Used Fishery
Management Vocabulary
• MSY: Maximum Sustainable Yield – the highest
number of fish people can harvest and still allow
the fish population to grow
• In theory, at MSY catch should = reproduction rate
• If catch < reproduction the population should grow
• If catch > reproduction the population will decrease
Can you see any problems with this theory?

14.
Strategies for Conservation
• Size Limits: used when we want fish to have a
chance to grow, reproduce. Ex: 28”
• Catch (bag) limits: establish how many can be taken
in a given time frame. ex: Two fish per day
• Closed areas: establish no-take areas. ex: Spawner
Sanctuaries & MPA’s (Marine Protected Areas). ex:
Nature Conservancy property in GSB, LI and MPA’s
in CA
http://www.youtube.com/watch?v=8wmpBK65vw4

15.
Strategies for Conservation cont.
• Gear restrictions: limit the ways people can harvest.
ex: No trawling allowed, trap fishing only
• Seasons: limit time frame for harvesting. Ex: No
harvesting during breeding season
• Licensing: limit the number of fishing licenses given
out
• Sex limits: limit harvest on a particular sex (Note:
this only works if species is sexually dimorphic)

17.
Magnuson – Stevens Fishery &
Management Act
• Named after senators from Washington state
and Alaska who sought to more appropriately
exploit fisheries in our EEZ
• Originated in 1976
• Last revised in 2007 (see next slide)

18.
Most updated Magnuson – Stevens Fishery
Conservation & Management Act goals, paraphrased:
•
•
•
•
•
•
•
•
•
•
Prevent overfishing while achieving optimum yield.
Use best scientific information available.
Manage stocks as a unit throughout their range; manage interrelated stocks as a
unit or in close coordination.
Not discriminate between residents of different states; any allocation of privileges
must be fair & equitable.
Promote efficiency, except that no such measure shall have economic allocation as
its sole purpose.
Take into account & allow for variations among & contingencies in fisheries, fishery
resources, & catches.
Minimize costs & avoid duplications.
Take into account the importance of fishery resources to fishing communities to
provide for the sustained participation of, & minimize adverse impacts to, such
communities (consistent with conservation requirements).
Minimize bycatch or mortality from bycatch.
Promote safety of human life at sea

21.
Reminder: Fisheries Managers deal
with a very dynamic living resource
AND people who may not have the
same ideas about sharing this resource
Watch the videos on this site and be prepared to
discuss in class:
http://www.shiftingbaselines.org/